Burner nozzle



Sept. 25, 1951 0, 155 2,569,033

BURNER NOZZLE Filed May 15, 1947 29 20' 2/ /.9 33 H 32. 31 zjgi 16 M v T535 IN VEN TOR. Maw/ 0 M5:

Patented Sept. 25, 1951 BURNER NOZZLE Morris 0. Wise, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application May 15, 1947, Serial No. 748,214

4 Claims.

This invention relates to burner nozzles; it is particularly concerned with nozzles for supplying fuel to the burner system of a gas turbine engine at a substantially constant pressure. In such systems there may be a relatively large number of nozzles receiving fuel under pressure from a common fuel manifold, and discharging the fuel into a series of burners individual to the respective nozzles or a single burner common to all nozzles; and it is important that the nozzles remain closed with a minimum of leakage or "drip until the manifold pressure attains a predetermined or given value, and then open and effectively discharge the fuel in the form of a fine conical spray; and the primary object of the invention is to provide a nozzle which will effectively meet such requirements.

Another object is to provide a burner nozzle which will produce atomization and a well rounded spray over a wide range of pressures ven though at the beginning of the range the pressure is at a relatively low value.

A further object is to provide a nozzle of the type specified which is reliable in operation and of relatively simple construction.

The foregoing and other objects and advantageswill become apparent in view of the following description taken in conjunction with the drawings, wherein:

Figure 1 is a substantially central longitudinal sectional view taken through a nozzle embodying the invention;

Figures 2 and 3 are cross sections taken substantially on the lines 22 and 3-4, Figure 1;

Figure 4 is a view in side elevation of the complete nozzle; and

Figure 5 is a central longitudinal section of a modified form of nozzle member.

Referring to the drawings in detail, Ill indicates the nozzle body which is hollow and defines an elongated fuel chamber I0, said body being formed with an external hex flange H and at one end has a reduced externally and internally screw threaded mounting shank l2. At its discharge end, the nozzle body is preferably recessed as at I: and formed with an internal flange l4. Mounted within the hollow central portion of the nozzle body is a nozzle member I! having a nozzle tip I! and a central spin chamber [6 terminated in an axial fuel, discharge passage or opening 11. A series of cross ducts it serve, when open, to communicate the fuel chamber It with the spin chamber It, said ducts projecting at a tangent to thespin chamber It so that as the fuel enters this chamber under pressure, it will have im- 2 parted thereto a whirling action which will produce a fine conical discharge spray from the opening ll.

Overlying the spin chamber is a closure member I9 which may be secured in place by having the surrounding metal peened thereover. The nozzle member l5 also has a hollow inner end wall 20 defining a chamber 20 in which is mounted a spring 2|, the chamber 20' being vented to the spin chamber 16 by means of a hole or opening 22 formed in the closure member H.

A flange 23, formed on the periphery of the nozzle member I5, is adapted to abut the flange it formed on the body member I0 and determine the location of the said nozzle member when the latter is press-fitted in the opening defined by the said flange. The peripheral surface of the wall 20 is preferably formed with one or more annular recesses 24, to catch foreign matter or abrasive particles and to facilitate a smooth sliding action between said surface and a piston type valve 25.

The nozzle member I5 is of a diameter such that when it is inserted in the fuel chamber I0 there is sufficient clearance to permit the piston valve 25 to be telescoped thereover and still leave a space for fuel in the chamber III, said piston 25 having a skirt 2 6 formed with a series of ports 21 which feed into an annular channel 28. When the channel 28 is in register with the ducts ll, fuel may flow into the whirl chamber l6 and thence be discharged through the tip opening IT.

A can 29 is threaded into the end of the body l0 and is formed with a passage 30 and a chamber 3| in which is mounted a check valve in the form of a ball 32 urged towards seated position by a spring 33.

To produce a relatively wide or full spray at pressures even as low as drip or leak pressures, one or more fine cross vents or bleeds 34 are formed in the nozzle member and communicate the fuel chamber I 0' with the spin chamber it beyond the skirt 26 of the piston 25, said vents or bleeds being arranged at a tangent to the said spin chamber in the same manner as the passages l8.

In operation, fuel under pressure from a fuel manifold or the like, not shown, enters at 30 and unseats the ball check valve 32 at a pressure of say, for example, twenty p. s. i. When the pressure of the fuel attains a value of, for example, ninety p. s. i. it depresses the piston 25 against the resistance of the spring 2i, and when the annular channel 28 registers with the tangential ducts l8, fuel flows under pressure from the fuel chamber I. into the swirl chamber it and is discharged from the nozzle opening II in the form of a fine swirling spray or cone.

when the manifold pressure drops below a predetermined value (ninety p. s. i. in the present instance) the piston fl retracts due to the force exerted by the spring II, the annular channel 28 moving out of registration with the tangential ports "and closing off fiow of fuel to the swirl chamber It.

The small cross vents or bleeds I4 communicate fuel under pressure to the spin chamber ,as soon as the check valve opens, and if there is any leakage fuel flowing from the chamber fl into the spin chamber at this time, it is caught in the swirl and diffused in a fine conical spray as it issues from the nozzle opening. There is thus sub-4 stantially -no drip" from the nozzle. Also, if desired, the check valve can be set to open at very low pressures and produce an initial fine starting discharge spray before the piston valve 25 leakage or "drip from the discharge opening II.

By venting the leakage fuel to the spin chamber arrnozzle'tip, no sealing bellows is necessary as in certain other types of nozzles. The nozzle assembly is relatively simple and can be made at a relatively low cost in view of the exactitude required of burner nozzles for gas turbine burner systems.

In Figure 5 the nozzle member, indicated at II. is generally similar to the nozzle member ll of the preceding figures except in this instance the chamber 3', which corresponds to the chamber II of Figure 1, is vented directly to the nonle tip. by way of longitudinal passages 31 instead of being vented to the spin chamber II, the latter being closed by a member ll corresponding to the member I I of Figure 1, except that it lacks the opening ff. Parts which conform exactly to those of thenozzle member of Figure 1 are given similar reference numerals. This type of nozzle member may prove desirable in certain instances, but it lacks the low prusure spin .feature of the nozzle member II.

It will be understood that certain minor changes in construction and design may be adopted without departing from the scope of the invention as defined by the appended claims.

I claim:

1. A burner nozzle comprising a nozzle body 'formed with a fuel chamber adapted to receive fuel under pressure, a nozzle member fixed in said fuel chamber and formed with a nozzle tip and a spin chamber terminating in a fuel discharge opening substantially centrally of said tip, the nozzle member being also formed with one or more fuel ducts or passages disposed at a tangent to said spin chamber. for conducting fuel from said fuel chamber to said spin chamber, avalve in thefnrm of a hollow piston telescoped over said nozzle member and having a skirt portion ooacting with said ducts, saidv piston valve tending to move in a direction to open said ducts when sub- Jected to the pressure of fuel in said fuel chamber, a spring interposed between said nozzle member and said piston, said spring normally urging the piston valve towards closed position and maintaining the valve closed at fuel pressures below 4 a predetermined value, means venting the chamber formed by said piston valve and said nozzle member to the spin chamber, said nozzle member being formed with one or more additional tangential fuel ducts of smaller diameter or fiow capacity than said first named fuel ducts communicating the fuel chamber with the spin chamber for admitting fuel to said spinchamber at fuel pressures below those required to open said piston valve.

' 2. A burner nozzle comprising a nozzle body formed with a fuel chamber and a fiow passage through which fuel flows under pressure to said chamber, a nozzle member fixed in said fuel chamber and formed with a nozzle tip and a fuel discharge opening substantially axially of said tip, the nozzle member being also formed with one or more fuel ducts or passages for conducting fuel from said fuel chamber to said discharge opening, a piston type valve arranged in sliding telescoping relation to said nozzle member for controlling admission of fuel from said fuel chamber through said ducts to said discharge opening, said piston valve tending to move in a direction to pass fuel to said discharge opening when subjected to the pressure of fuel in said fuel chamber, a spring normally urging said valve towards closed posh tion and maintaining the valve closed at fuel pressure below a predetermined value, a check valve disposed in said fiow passage leading to the fuel chamber, said check valve being adapted to remain closed at fuel pressures below a predetermined value and to open at a pressure lower than that required to open said piston valve and pass fuel to said fuel chamber, and passage means for conducting low pressure fuel from said latter chamber to said fuel discharge opening when said piston valve is closed and said check valve is open.

3. A burner nozzle comprising a nozzle body formed with an elongated fuel chamber having a fiow passage for the intake of fuel at one end of said chamber and a mounting fiange at the opposite end of said chamber, a nozzle member 1 adapted to be inserted in said chamber and held in fixed position by said fiange, said nozzle memher having a hollow skirt portion and a spin chamber terminating in a fuel discharge opening substantially axially of the nozzle tip, said nozzle member being also formed with fuel duets for communicating fuel under pressure from said fuel chamber to said spin chamber, said duets being disposed at a tangent to said 'spin chamber to cause the fuel to whirl in said latter chamberfa valve member in the form of a hollow piston telescoped over the skirt portion ofsaid nozzle mem ber and provided with fuel inlet ports leading to an annular passage adapted to register with said ducts when the valve member is subjected to fuel under predetermined pressure, a spring disposed in the skirt portion of said nozzle member and engaging said piston, said spring maintaining the piston valve closed at pressures below a predetermined value, and one or more vent passages venting the interior of said nozzle member past the chamber, a piston valve coacting with said nozzle member and arranged in sliding telescoping relation to said nozzle member for controlling admission of fuel to said spin chamber, said piston valve tending to move in a direction to pass fuel to said discharge opening when subjected to the pressure of fuel in said fuel chamber, a spring normally urging said valve towards closed position and maintaining the valve closed at fuel pressures below a predetermined value, and a check valve controlling flow of fuel into said fuel chamber, said check valve being adapted to close at fuel pressures below a predetermined value and close off flow of fuel to said fuel chamber, said nozzle member being formed with additional tangential passages communicating the fuel chamber with REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,172,556 Edwards Sept. 12, 1939 2,243,995 Alden June 3, 1941 2,294,029 High Aug. 25, 1942 2,387,690 Stelzel Oct. 23, 1945 

